Cost implications of low molecular weight heparins as prophylaxis following total hip and knee replacement

Deep venous thrombosis (DVT) and pulmonary embolism (PE) are serious and costly complications of total hip and knee replacement surgery. The risk of these complications is significantly reduced by prophylaxis. Low molecular weight heparins (LMWH) are being used for this indication with increased frequency. The objective of this study was to assess the cost implications of LMWH for the prevention of symptomatic DVT and PE complications following total hip and knee replacement surgery. The study design was cost analysis based on utilization and the costs of medical resources for prophylaxis and treatment of DVT/PE. A retrospective hospital data set was used to assess symptomatic DVT/PE complication rates and medical resource utilization in patients receiving warfarin, other, and no prophylaxis. The results of a clinical trial were used to estimate relative reductions in risk of symptomatic DVT/PE due to prophylaxis with LMWH. The 7721 total hip and knee replacement patients analyzed were admitted in 1992 in 57 acute-care non-federal hospitals. The measurements were of incremental costs or charges expected to be saved as a result of using LMWH prophylaxis instead of warfarin prophylaxis. Prophylaxis using LMWH rather than warfarin reduces the expected total costs (charges) of treatment by $50 ($193), not including the pharmaceutical costs associated with prophylaxis. The cost reduction in favor of LMWH was sensitive to several factors, including blood monitoring costs and DVT/PE complication rates. Where a reduction of one day in hospital stay could be realized from LMWH's early onset of action, the cost (charges) reduction increased to $226 ($624). In conclusion, LMWH has the potential to offer several short- and long-term cost advantages compared with warfarin, mostly due to lower test costs associated with prophylaxis and reduced complication rates.     

Venous thromboembolism prophylaxis in medically ill patients: a mixed treatment comparison meta-analysis

The American College of Chest Physicians guidelines recommend unfractionated heparin (UFH), low molecular weight heparins (LMWHs) or fondaparinux for prevention of venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism (PE), in medically-ill patients. Direct oral anticoagulants (DOACs) have been evaluated relative to enoxaparin for VTE prophylaxis though head-to-head comparisons of these agents are lacking. Therefore, we conducted a mixed treatment comparisons meta-analysis to evaluate the safety and efficacy of established treatments and DOACs for VTE prophylaxis in medically-ill patients. A comprehensive literature search was conducted to identify randomized trials evaluating UFH, LMWHs or DOACS for the prevention of VTE in medically ill patients. Articles were retrieved and cross-referenced for additional trials, evaluated and entered into ADDIS (version 1.16.6) to generate direct and indirect treatment comparisons for VTE, DVT, PE, death from any cause, and bleeding. Ten articles were included and eight anticoagulants were evaluated in a treatment network representing data on 28,382 patients. We found each treatment had similar efficacy in preventing VTE, DVT, PE, death from any cause and each had similar risk of minor and major bleeding. Overall, placebo was associated with more VTE and DVT events compared to LMWHs and DOACs. We found that UFH, LMWHs and DOACs are comparable in preventing VTE, DVT, PE, and death from any cause and in association with minor and major bleeding. Anticoagulant selection for VTE prophylaxis in medically-ill patients should be individualized by patient characteristics, risks and preferences along with specific pharmacokinetic and pharmacodynamic considerations.     

Prophylaxis against venous thromboembolism in hospitalized medical patients: an evidence-based and practical approach

To discuss the evidence regarding the efficacy and safety of anticoagulant prophylaxis against deep vein thrombosis (DVT) in hospitalized medical patients; to understand barriers to implementation of prophylaxis and how they can be overcome; and to have a practical approach as to which patients should and should not receive anticoagulant prophylaxis. The frequency of DVT in hospitalized medical patients, in the absence of prophylaxis varies from 10-15%. Autopsy studies have shown that pulmonary embolism (PE) is associated with 5-10% of deaths in hospitalized patients. With appropriate use of anticoagulant prophylaxis, there is a 57% reduction in the risk for symptomatic PE (relative risk [RR] 0.43, 95% CI 0.26-0.71), a 62% reduction in the risk for fatal PE (RR 0.38, 95% CI 0.21-0.69), and a 53% reduction in the risk for symptomatic DVT (RR 0.47, 95% CI 0.22-1.00). Anticoagulant prophylaxis is also associated with a non-significant increased risk for major bleeding (RR 1.32, 95% CI 0.73-2.37). Risk factors for DVT and bleeding in medical patients may help to identify patients in whom anticoagulant prophylaxis is indicated or contraindicated but validated risk stratifications schemes are lacking. Among hospitalized medical patients, randomized trials have established an acceptable therapeutic benefit-to-risk ratio of anticoagulant prophylaxis to reduce the incidence of clinically silent and symptomatic venous thromboembolism, including a reduction in the incidence of fatal PE. Additional research is needed to develop a validated risk stratification model for hospitalized medical patients that can help identify patients who would benefit most from anticoagulant prophylaxis.     

Venous thromboembolism (VTE) in hospitalized cancer patients: prophylaxis failure or failure to prophylax!

Cancer patients are at higher risk for venous thromboembolism (VTE). Anticoagulants, when used for prophylaxis, had successfully reduced the incidence of VTE in high risk patients. Nevertheless, many registry studies have shown low compliance rate with published prophylaxis guidelines. From January 2004 through June 2008, hospital database was searched for all discharge diagnoses of cancer with deep vein thrombosis (DVT) and/or pulmonary embolism (PE). Prophylaxis rate for the whole group and for subgroups in relation to recent hospitalization, duration of cancer diagnosis and number of other coexisting risk factors were studied. Two hundred patients were identified; majority (91.8%) had advanced-stage cancer at time of VTE diagnosis. In addition to cancer, many patients had multiple coexisting risk factors for VTE with 137 (68.5%) patients had at least three while 71 (35.5%) had four or more. Overall, 111(55.5%) patients developed lower-extremity DVT while 52 (26%) patients developed PE, other sites accounted for 18%. Majority of the patients (72%) had VTE diagnosed within the first 12 months following cancer diagnosis. Almost three quarters of the patients (73.5%) had not received any antecedent prophylaxis. Prophylaxis rate was 23% among patients with ≥3 risk factors and 50% among the highest risk group with ≥5 risk factors. Based on our findings, majority of VTE in cancer patients occurred due to failure to offer prophylaxis, minority were due to prophylaxis failure. Meticulous quality improvement programs should be established to emphasize the importance of implementing more intensive prophylaxis among high-risk cancer patients.     

Selection of medical patients for prophylaxis of venous thromboembolism based on analysis of the benefit–hazard ratio

Background:  Medical patients may benefit from anticoagulant prophylaxis of venous thromboembolism (VTE), but assessment of thrombotic risk is complex. I describe a method for estimating the minimum thrombotic risk required to ensure that a reasonable benefit–hazard ratio is maintained.
Methods:  An equation was derived relating baseline VTE risk and a minimum acceptable benefit–hazard ratio ( R ), defined as 'pulmonary embolus (PE) alone', 'PE or symptomatic proximal deep venous thrombosis (DVT)', or 'PE or any symptomatic DVT' prevented per major bleeding. The equation was used to estimate the relative risk (RR) of thromboembolism required for net benefit (main outcome measure). The PREVENT study was the primary data source, backed by data from two meta-analyses.
Results:  For R ranging from 3 to 10, the RR required for net beneficial prophylaxis was 6.5–21.6 (PE alone); 3.0–9.9 (PE or symptomatic proximal DVT); and 2.3–7.6 (PE or any symptomatic DVT), respectively. These RR are possible only in the presence of risk factors of high weighting. Sensitivity analysis showed that the findings were robust to changes in baseline assumptions related to thrombosis and bleeding rates.
Conclusion:  A method for risk assessment for medical thromboprophylaxis has been developed. The results suggest that only a minority of medical patients with high RR should receive prophylaxis.     

Should we give thromboprophylaxis to patients with liver cirrhosis and coagulopathy?

Patients with liver cirrhosis are characterized by decreased synthesis of both pro- and anticoagulant factors, and recently there has been evidence of normal generation of thrombin resulting in a near normal haemostatic balance. Although it is generally recognized that bleeding is the most common clinical manifestation as a result of decreased platelet function and number, diminished clotting factors and excessive fibrinolysis, hypercoagulability may play an under recognized but important role in many aspects of chronic liver disease. In fact, they can encounter thrombotic complications such as portal vein thrombosis, occlusion of small intrahepatic vein branches and deep vein thrombosis (DVT). In particular, patients with cirrhosis appear to have a higher incidence of unprovoked DVT and pulmonary embolism (PE) compared with the general population. In dedicated studies, the incidence of DVT/PE ranges from 0.5% to 1.9%, similar to patients without comorbidities, but lower than patients with other chronic diseases (i.e, renal or heart disease). Surprisingly, standard coagulation laboratory parameters are not associated with a risk of developing DVT/PE; however, with multivariate analysis, serum albumin level was independently associated with the occurrence of thrombosis. Moreover, patients with chronic liver disease share the same risk factors as the general population for DVT/PE, and specifically, liver resection can unbalance the haemostatic equilibrium towards a hypercoagulable state. Current guidelines on antithrombotic prophylaxis do not specifically comment on the cirrhotic population as a result of the perceived risk of bleeding complications but the cirrhotic patient should not be considered as an auto-anticoagulated patient. Therefore, thromboprophylaxis should be recommended in patients with liver cirrhosis at least when exposed to high-risk conditions for thrombotic complications. Low molecular weight heparins (LWMHs) seem to be relatively safe in this group of patients; however, when important risk factors for bleeding are present, graduated compression stockings or intermittent pneumatic compression should be considered.     

Deep vein thrombosis and pulmonary embolism: prevention, diagnosis, and treatment.

Pulmonary embolism (PE) is a significant cause of mortality in the elderly. More than 90% of pulmonary emboli originate from a thrombus in the deep veins of the legs. Proper diagnosis and treatment of deep vein thrombosis (DVT) are thus essential to prevent PE. Diagnosis of new or recurrent DVT is based on the results of one or more tests, including impedance plethysmography (IPG) or duplex venous scan; venography can often be avoided, based on results of initial testing. For suspected PE, perfusion lung scanning is the initial test of choice, followed by IPG/duplex or venography. Pulmonary angiography is indicated for patients with decreased cardiorespiratory reserve. Decisions governing prophylaxis of DVT are based on individual relative risk; prophylactic therapies include intermittent compression, low-dose heparin, and oral anticoagulants. Management of thromboembolism requires IV and oral anticoagulant therapy.     

Venous Thromboembolism in Cancer Patients Referred to the American University of Beirut—Medical Center Secondary to Deep Vein Thrombosis; Occurrence and Risk Factors

Background/objectives: Cancer is a very important risk factor for the development of thromboembolic disorders. We conducted a retrospective study, in order to examine the rate of Deep vein thrombosis occurrence in cancer patients, as well as the effects of risk factors for DVT in cancer patients affected with DVT. Methods: 148 patients were enrolled in this study. Several risk factors for DVT were retrospectively examined with the main emphasis being age, gender, obesity, previous history of past thromboembolic phenomena and metastatic disease. Results: 55.5% of the study group was older than 60 years of age. Gender did not appear to be a significant risk factor. As for obesity, only 23% of our patients were defined as obese. An examination of previous history of thromboembolic conditions revealed that 16.8% had previous history of DVT, 1.3% developed a PE prior to presentation and 3.4% were positive for both DVT and PE. As for metastasis, 33.7% of our study population exhibited metastatic cancer upon their presentation. One interesting finding was that only 13 patients out of the 148 had been on DVT-prophylaxis prior to their admission. Conclusion: Cancer is an important risk factor for the development of thromboembolic phenomena, yet in most parts of the world, prophylaxis is discerned mostly through clinical judgement or local guidelines. With this in mind, and the additive effects of other risk factors, stricter medical practices and well-defined regimens should be set forth to protect cancer patients from these conditions.     

Efficacy and safety of anticoagulant prophylaxis to prevent venous thromboembolism in acutely ill medical inpatients: a meta-analysis

Objectives. Venous thromboembolism (VTE) is a potentially serious complication of hospitalization and immobilization. The use of anticoagulant prophylaxis in acutely ill medical inpatients is still under debate. New data including a recent meta‐analysis have recently been published. We aim at studying the efficacy and safety of anticoagulant prophylaxis in acutely ill medical inpatients, and demonstrate differences between meta‐analyses due to different data extraction from the heterogeneous studies included. Subjects. The Cochrane Library, MEDLINE and EMBASE were searched from 1980 to present. Manual searches were performed regarding abstracts from major meetings. Seven blinded randomized controlled clinical trials assessing the prophylactic effect of heparin in acutely ill medical patients were identified and included in the meta‐analysis. Results. Low‐molecular weight heparin (LMWH) prophylaxis prevented 48% of symptomatic pulmonary embolism (PE), 48% of symptomatic deep vein thrombosis (DVT) (not significant) and 51% of asymptomatic DVT. A nonsignificant trend towards higher bleeding risk during LMWH prophylaxis was found. Death was not significantly affected. We compared our data with a recent meta‐analysis with different study selection and data extraction and found similar results. Conclusions. As DVT and PE are manifestations of the same illness, VTE, one can argue that anticoagulant prophylaxis prevents approximately half of the expected events. Most medical inpatients have short hospital stays, and a low risk of VTE. The important task for the clinician is to identify patients with a sufficiently high risk of symptomatic VTE to warrant LMWH prophylaxis. Despite differences in study selection and data extraction, our study shows results similar to a recent meta‐analysis.     

Prevention of venous thromboembolism

Recognition of the patient at risk and delivery of appropriate prophylaxis are imperative to reduce the incidence of VTE (including fatal PE) in hospitalized patients. This article provides estimates of risk and a summary of effective prophylaxis methods such that physicians can tailor an individual patient's prophylaxis regimen to maximize DVT risk reduction in the safest and most cost-effective manner.     

Rates of initial and recurrent thromboembolic disease among patients with malignancy versus those without malignancy. Risk analysis using Medicare claims data.

Although the association between malignancy and thromboembolic disease is well established, the relative risk of developing initial and recurrent deep vein thrombosis (DVT) or pulmonary embolism (PE) among patients with malignancy versus those without malignancy has not been clearly defined. The Medicare Provider Analysis and Review Record (MEDPAR) database was used for this analysis. Patients hospitalized during 1988-1990 with DVT/PE alone, DVT/PE and malignancy, malignancy alone, or 1 of several nonmalignant diseases (other than DVT/PE) were studied. The association of malignancy and nonmalignant disease with an initial episode of DVT/PE, recurrent DVT/PE, and mortality were analyzed. The percentage of patients with DVT/PE at the initial hospitalization was higher for those with malignancy compared with those with nonmalignant disease (0.6% versus 0.57%, p = 0.001). The probability of readmission within 183 days of initial hospitalization with recurrent thromboembolic disease was 0.22 for patients with prior DVT/PE and malignancy compared with 0.065 for patients with prior DVT/PE and no malignancy (p = 0.001). Among those patients with DVT/PE and malignant disease, the probability of death within 183 days of initial hospitalization was 0.94 versus 0.29 among those with DVT/PE and no malignancy (p = 0.001). The relative risk of DVT/PE among patients with specific types of malignancy is described. This study demonstrates that patients with concurrent DVT/PE and malignancy have a more than threefold higher risk of recurrent thromboembolic disease and death (from and cause) than patients with DVT/PE without malignancy. An alternative management strategy may be indicated for such patients.     

Risk of pulmonary embolism and/or deep venous thrombosis in Asian-Americans

Several reports from Asian countries suggest a low prevalence of pulmonary embolism (PE) and deep venous thrombosis (DVT) in Asians, and sparse US data show that a slightly higher prevalence of PE/DVT in "nonwhites" than in whites is evident in all geographic regions except the Pacific region (California, Oregon, and Washington) where "nonwhites" include a larger proportion of Asians and Hispanics than in other US locations. We prospectively studied PE/DVT hospitalizations in 128,934 persons in relation to traits determined at health examinations in 1978 to 1985. Through 1994, 337 persons were subsequently hospitalized for PE and/or DVT (for PE first, n = 206). Cox proportional-hazards models with 9 covariates were used. In multivariate models, the following RRs (95% confidence intervals) were found for PE/DVT combined: black/white = 1.1 (0.4 to 1.4); Hispanic/white = 0.7 (0.3 to 1.5); and Asian/white = 0.2 (0.1 to 0. 5; p = 0.002). The lower risk of Asians was present in each sex and for persons first hospitalized for either PE or DVT. Covariates with significant positive relations to risk were age, male sex, body mass index, and a composite coronary disease risk/symptom variable; covariates not significantly related were education, marital status, smoking, and alcohol. These data suggest that Asians have very low risk of PE/DVT, which may account for US geographic variations in white/non-white risk differences. Possible explanations include the absence of hazardous mutations or unspecified PE/DVT protective traits in Asians.     

Predicting of Venous Thromboembolism for Patients Undergoing Gynecological Surgery

The purpose of this study was to determine the risk stratification of deep venous thrombosis (DVT) in patients undergoing gynecological surgery.A retrospective study was conducted with a cohort of 739 consecutive female patients undergoing gynecological surgery between May 2008 and July 2013 in Beijing Chao-yang hospital. DVT of the leg was detected using complete compression and color Doppler ultrasound. Pulmonary embolism (PE) was diagnosed by computed tomography pulmonary angiogram (CTPA).The overall incidence of DVT was 9.20% (68/739) in this patient population, including 16 (2.17%) symptomatic DVT and 52 (7.04%) silent DVT. A total of 66 (97.06%) DVT events were found within 7 days of surgery and 2 (2.94%) after 1 week. 94.82% thrombi were located in distal vein, and the rest 5.18% located in proximal and distal veins. Among the 68 patients with DVT, 46 patients with suspected PE received CTPA and 21 (45.65%) were confirmed with PE.Six independent factors including varicose vein, bed rest time ≥48 h, length of operation ≥3 h, laparotomy surgery, hypertension, and age ≥50 years significantly increased the incidence of postoperative DVT on multivariate analysis. Patients with none risk factor are at low risk, with 1 or 2 risk factors are at moderate risk, and with ≥3 factors are at high risk of DVT.The incidence of postoperative DVT and PE after gynecological surgery is high in patients with moderate or high-risk level. Noninvasive detection of DVT in 7 days after surgery is necessary because most patients showed no typical symptoms. Appropriate prophylaxis could be performed in patients at moderate or high risk of DVT.     

Economic analysis of low-dose heparin vs the low-molecular-weight heparin enoxaparin for prevention of venous thromboembolism after colorectal surgery.

BACKGROUND: Low-dose heparin and low-molecular-weight heparin are effective strategies for preventing venous thromboembolism in colorectal surgery. The economic attractiveness of these 2 strategies in North America is unknown. We conducted an economic analysis of low-dose heparin calcium compared with enoxaparin sodium, a low-molecular-weight heparin, for thromboembolism prophylaxis after colorectal surgery. METHODS: We used decision analysis, with an economic perspective of a third-party payer. Efficacy data were obtained from the Canadian Multicentre Colorectal Deep Vein Thrombosis Prophylaxis Trial and a literature review. Canadian costs for diagnosis and treatment of deep vein thrombosis (DVT), pulmonary embolism (PE), and major bleeding were obtained from chart review and a national hospital database of colorectal surgery; American costs were obtained from published literature. The main outcomes were incremental benefits (symptomatic DVTs, symptomatic PEs, and major bleeding events avoided) and incremental costs for every 1000 patients treated. RESULTS: In the Canadian Colorectal Trial, the relative risk of DVT and PE for enoxaparin compared with low-dose heparin was 1.0 (95% confidence interval, 0.7-1.5), and the relative risk of major bleeding was 1.8 (95% confidence interval, 0.8-3.9). With the use of these data in the baseline analysis, a strategy of enoxaparin prophylaxis was associated with equal numbers of symptomatic DVTs and PEs, and an excess of 12 major bleeding episodes for every 1000 patients treated, with an additional cost of $86 050 (Canadian data) or $145 667 (US data). In a sensitivity analysis using optimal assumptions for efficacy and safety of enoxaparin (relative risk of DVT, 0.8; relative risk of PE, 0.4; relative risk of major bleeding, 1.0), a strategy of enoxaparin prophylaxis was associated with 0.8 fewer symptomatic DVT, 3 fewer symptomatic PEs, and equal numbers of major bleeding episodes for every 1000 patients treated, with an additional cost of $15 217 (Canadian data) or $107 614 (US data). CONCLUSION: Although heparin and enoxaparin are equally effective, low-dose heparin is a more economically attractive choice for thromboembolism prophylaxis after colorectal surgery.     

Deep venous thrombosis. Implications after open heart surgery

We reviewed the cases of 10,638 cardiac surgical patients to determine the incidence of deep vein thrombosis (DVT) after open heart surgery (OHS). Seventy-seven patients (0.7 percent) had DVT. Group 1 included 36 patients who had DVT without pulmonary embolism (PE). Occurrence was equal in either leg. Anticoagulation with heparin and warfarin sodium (Coumadin) was employed as treatment. Extension of hospital stay was 10.8 days. Group 2 consisted of 41 patients who experienced PE 9.9 days after OHS. Sixteen patients had known DVT and were receiving heparin. In 25 patients, PE was the first event. Risk factors for PE included perioperative myocardial infarction (16 percent), atrial fibrillation (41 percent); blood type A (70 percent) (p less than 0.05), and coronary artery bypass graft (CABG) (98 percent). Twenty-four patients were treated with anti-coagulation alone. Six died of recurrent PE; mortality was 25 percent. Seventeen patients received anticoagulation plus inferior vena cava (IVC) interruption using a Hunter balloon. There were no recurrent PEs and there was one death from myocardial infarction (6 percent). Deep vein thrombosis and PE are rare complications of OHS. Routine prophylaxis with either heparin or warfarin is unnecessary. Patients with DVT, atrial fibrillation (AF), and perioperative myocardial infarction are at high risk of PE. Aggressive diagnosis to identify major venous thrombi along with anticoagulation and early consideration of IVC interruption are recommended for these patients. Patients who have undergone OHS and who have PE are at an unusually high risk for recurrent PE with death and are more safely treated with IVC interruption and anticoagulation than anticoagulation alone.     

Acute pulmonary embolism

Deep vein thrombosis (DVT) and, therefore, pulmonary embolism (PE) are often preventable. Because of the lack of specificity of symptoms and signs, DVT and PE are frequently clinically unsuspected, leading to substantial diagnostic and therapeutic delays and resulting in considerable morbidity and mortality. Furthermore, prophylaxis continues to be dramatically underused. The incidence of venous thromboembolism is high in hospitalized patients, and both surgical as well as medical patients are at risk.     

Venous thromboembolism prophylaxis for medical service-mostly cancer-patients at hospital discharge

Objective

Many hospitalized Medical Service patients remain at high risk for venous thromboembolism (VTE) after hospital discharge. Our aim was to compare the effect of the use or omission of extended pharmacologic VTE prophylaxis after hospital discharge among Medical Service patients on the incidence of symptomatic deep vein thrombosis (DVT) or pulmonary embolism (PE) over the ensuing 3 months.

Methods

In this case-control study, we identified a case population of 461 patients for whom parenteral pharmacological VTE prophylaxis was prescribed to continue after discharge and matched them according to age, sex, and VTE risk score to a control group of 922 patients for whom VTE prophylaxis was not continued after discharge.

Results

The primary endpoint of symptomatic DVT or PE at 90 days occurred in 5.0% of patients receiving extended prophylaxis compared with 4.3% of patients who received no prophylaxis after discharge (P = .58). Fewer patients were alive at 90 days in patients receiving extended pharmacologic VTE prophylaxis, compared with those who received no prophylaxis after discharge (56.8% vs 68.4%, P <.001). Major bleeding, defined as those events requiring blood transfusion, medical, or surgical intervention, occurred more frequently in patients receiving extended VTE prophylaxis after discharge than in those patients who received no prophylaxis after discharge (3.9% vs 1.9%, P = .03).

Conclusion

Extended pharmacologic thromboprophylaxis in high-risk Medical Service patients did not reduce symptomatic DVT and PE in the ensuing 90 days after hospital discharge. There was a higher incidence of all-cause death and major bleeding episodes in patients receiving extended prophylaxis. Our observations do not support the routine use of extended VTE prophylaxis in Medical Service patients. Further research is needed to identify patients who may benefit from extended pharmacologic VTE prophylaxis and those who may have too great a bleeding risk.     

Double trouble for 2,609 hospitalized medical patients who developed deep vein thrombosis: prophylaxis omitted more often and pulmonary embolism more frequent

BACKGROUND: Hospitalized patients with medical illness are especially susceptible to the development of venous thromboembolism (VTE). METHODS: To improve our understanding of the demographics, comorbidities, risk factors, clinical presentation, prophylaxis, and treatment of hospitalized medical patients with deep vein thrombosis (DVT), we evaluated hospitalized medical patients in a prospective registry of 5,451 consecutive ultrasound-confirmed DVT patients at 183 institutions in the United States. RESULTS: Of those patients who participated in the registry, 2,609 (48%) were hospitalized medical patients. Compared with 1,953 hospitalized nonmedical patients with DVT, medical patients with DVT experienced pulmonary embolism (PE) more often (22.2% vs 15.5%, respectively; p < 0.0001). However, medical patients in whom DVT developed had received VTE prophylaxis far less frequently than nonmedical patients (25.4% vs 53.8%, respectively; p < 0.0001). The underutilization of VTE prophylaxis among hospitalized medical patients extended to both pharmacologic and mechanical modalities. In a multivariable logistic regression analysis of all hospitalized VTE patients, status as a medical patient was negatively associated with receiving prophylaxis (adjusted odds ratio, 0.47; 95% confidence interval, 0.28 to 0.78). CONCLUSIONS: Hospitalized medical patients face "double trouble." First, during hospitalization for a reason other than VTE, VTE prophylaxis is omitted in medical patients more often than in nonmedical patients. Second, when VTE develops as a complication of hospitalization, hospitalized medical patients experience PE more often. Further studies should focus on understanding why prophylaxis is often omitted in hospitalized medical patients and on improving its implementation in this vulnerable population.     

Extended venous thromboembolism prophylaxis after colorectal cancer surgery: the current state of the evidence

There is level one evidence to support combined mechanical and chemical thromboprophylaxis for 7–10 days after colorectal cancer surgery, but there remains a paucity of data to support extended prophylaxis after discharge. The aim of this clinical review is to summarise the currently available evidence for extended venous thromboprophylaxis after elective colorectal cancer surgery. Clinical review of the major clinical guidelines and published clinical data evaluating extended venous thromboprophylaxis after elective colorectal cancer surgery. Five major guideline recommendations are outlined, and the results of the five published randomised controlled trials are summarised and reviewed with a specific focus on the efficacy and cost-effectiveness of extended heparin prophylaxis to prevent clinically relevant post-operative venous thromboembolism (VTE) after colorectal cancer surgery. Extended VTE prophylaxis after colorectal cancer surgery reduces the incidence of asymptomatic screen detected deep venous thrombosis (DVT) only, with no demonstrable reduction in symptomatic DVT, symptomatic PE, or VTE related death. Evidence for cost-effectiveness is limited. As the incidence of clinical VTE is very low in this patient subgroup overall, future research should be focused on higher risk patient subgroups in whom a reduction in VTE may be both more demonstrable and clinically relevant.     

The effect of a computerized reminder system on the prevention of postoperative venous thromboembolism

STUDY OBJECTIVE: To measure the effect of an altered process of care, directed by a computerized reminder system, on rates of symptomatic postoperative venous thromboembolism. DESIGN: Comparisons of preintervention and postintervention measurements. SETTING: A university-affiliated community hospital in Utah. PATIENTS: Two-thousand seventy-seven consecutive patients who underwent major operations in four surgical divisions between January 1, 1997, and October 31, 1997 (preintervention), and 2,093 consecutive patients who underwent the same procedures between January 1, 1998, and October 31,1998 (postintervention). INTERVENTION: A program to prevent venous thromboembolism developed from American College of Chest Physicians guidelines, and an altered work process directed by a computerized reminder system. MEASUREMENTS: Rates of symptomatic, objectively confirmed deep vein thrombosis (DVT), pulmonary embolism (PE), and death attributable to venous thromboembolism occurring within 90 days of the date of surgery. RESULTS: The preintervention and postintervention cohorts did not differ with respect to age, severity of illness, number of risk factors for venous thromboembolism, or individual risk factors for venous thromboembolism. The overall prophylaxis rate increased from 89.9% before implementation of the computerized reminder system to 95.0% after implementation (p < 0.0001). The combined 90-day rate of symptomatic DVT, PE, and death attributable to PE remained the same (preintervention, 1.0%; postintervention, 1.2%; odds ratio, 1.21; 95% confidence interval, 0.67 to 2.20). Forty of 46 venous thromboembolic complications (87%) occurred despite the delivery of American College of Chest Physicians-recommended measures to prevent venous thromboembolism. CONCLUSIONS: Computerized reminder systems combined with altered care procedures increase the rate of prophylaxis against venous thromboembolism without decreasing the rate of symptomatic venous thromboembolism when the baseline rate of prophylaxis is high. A population of surgical patients exists who are resistant to American College of Chest Physicians-recommended prophylactic measures against venous thromboembolism. New strategies are needed to address prophylaxis-resistant venous thromboembolism.